What are important features in a listening chair

It has to be a design that allows spikes to replace the original chair feet, so that it makes you mechanically grounded with the speakers when sitting in it. Especially beneficial with vibrations induced with higher DB's.
8^0   

Build style and materials is a personal thing, but the height it places your ears at is very important depending on the speaker type and design.

i.e. ESL/Planar speakers sound best when your ears are somewhere in front of the panels. (not above......... or below)

Box designs your ears should be close to level with the tweeter.  That's been my personal experience. 

My custom made Gilmartin Rocking chair.  Sized to my body and much, much more comfortable then it looks.  Since it was sized to fit me, it offers great back support.  Difficult to get visitors out of the chair once they sit down.  Also looks outrageous. (The chair at the top.)

https://www.pinterest.com/pin/55450639136286625/

I've got a shock-absorbing high-speed chair from a SEAL attack boat with a 15" Eminence driver attached under the seat. Bass you can truly feel, but hard on the prostate.

That Gilrmartin Rocking chair is beautiful. It must have cost a small fortune, but to have it tailored to your body makes it worth it. We need more craftsman like that.

All the best,
Nonoise

@dsotm073 - Have you seen the "Pelican Chair"? Looks like it blocks side-wall reflections before they reach you!